Turret Wheel Bearing systems are known from U.S. Pat. No. 6,269,762 Vessel—turret assembly having radially guided bogie wheels and U.S. Pat. No. 5,359,957 Turret for Drilling or Production Ship.
Turret wheel bearing systems known have cylindrically shaped wheels.
Both these solutions have bogie wheels requiring two tracks. They are designed for large turret loads. Boggy systems are too comprehensive for less loaded turret bearings.
Turrets with single wheel systems such as the GNO patented turret bearing system are based on load sharing through a complicated hydraulic system involving a number of elements and wearable parts.
Other systems such as the AmClyde system is based on structural stiffness of a rigid structure with very small load sharing capabilities requiring very accurate machining of the various parts and vessel induced vessel deformations affects the load response substantial.
One major disadvantage with the cylindrically shaped wheels is that there will be substantial wear caused by relative movements between the wheel and the rail at the inward and the outward portions of the contact surfaces between the wheel and the rail. The reason is the longer circumference of the outward face of the rail than the inward face of the rail in combination with the great wheel width compared with the rail diameter.